History of the Oldwalls: Part I

 is a quest in Bastard's Wound.

Synopsis
Mell has asked you to enter the Oldwalls to find and bring back Sage Lexeme and Reef-Talon. He thinks Lexeme can help fix whatever is wrong with Reef-Talon and bring peace back to the Wound.

Acquisition
It is easy to miss this quest, since it is only available if you refuse to side with either Wagstaff or Jaspos. In order to start this quest, you must first complete both the competing leaders' fetch-quests (Jaspos' Knapping on the Job and Wagstaff's Tide Together), then speak to Mell. If you've accepted either Blood of the Beast or Bones of the Beast, Mell will not offer this alternative quest.

Walkthrough

 * To unlock the depths, head to Insipid Moniker. If you completed Midnight Wanderer, you can leverage the knowledge and intimidate her. Otherwise, you can use Athletics 57 or Lore 52. You receive the Bastard's Wound Oldwalls Keystone. Head to the easternmost portal (the one where Moniker fought off the Bane attack) and use it to enter The Abyss.
 * Defeat the war party sent to find Reef-Talon and grab the Lazu torchkey. Approach the stairs to talk to Reef-Talon. No matter what you say, she will flee into the Oldwalls.
 * You need three torchkeys to lower the stairs: Lazu, Cymo torchkey, and Jadis torchkey. (Note that to access the locations of these keys, it is vital to remember that you can interact with the torches at a distance, across gaps you can't cross.) Once you have all three, use them on the three beacons in the Abyss (Lazu, Jadis, Cymo, counter-clockwise) and ascend the steps.
 * You will find Lexeme beyond. Talk to her. Bringing Lantry along results in a touching moment for them both, and is a part of his companion quest. Talking to her completes the first part of the quest. If you agree to help Reef-Talon, she will give you the Tanza torchkey.

Bug
Important note: Examining the murals before you're told to examine them by Lexeme and help Reef-Talon (i.e. at this point) can trigger a bug that will render the expansion uncompletable without a patch. Keep that in mind.